Among the display technologies, Organic Light-Emitting Diode (OLED) is regarded in the industry as the third-generation display technology subsequent to Liquid Crystal Display (LCD) due to its advantages of a thin and light characteristic, active luminescence, fast response speed, wide visual angle, abundant colors, high brightness, low power consumption, high and low temperature resistance and the like.
At present, OLED displays are mainly displays that emit light under the control of electric current, and the luminescence uniformity is controlled by the corresponding electric current. However, because the threshold voltage of the drive transistor of each pixel of the OLED display tends to be drifted over time, the electric current passing through the OLED may be deviated under the same data signal, which causes non-uniform brightness in displaying. Further, the luminous efficiency of the OLED device itself may degrade over time, and thus the brightness may be lowered under the same electric current, thereby lowering the display effect of the display.